The MAKING-CITY project is now 21-months live and the consortium members are working jointly to determine by the end of the project valid and replicable standards to be the core of specific urban transition planning processes aligned with the vision and the goals of the cities.
According to the project’s Grant Agreement the participants partners in charge of the “Demonstration of Positive Energy District” workpackage have started to purchase field experimentation to study technical solutions which could in the future be implemented in the PED models and processes.
The demo houses project will promote the definition of a new concept of intervention related to the extensive retrofitting of homes. The consortium partners in charge are focusing on the retrofitting options of three individual buildings, terrace houses in the North PED of Groningen. For these three households different combinations of innovative and conventional technics were selected, based on calculations, to make these households energy positive.
The selection of Demo houses
To recruit the homes which will embody the demohouses project, the local partners have organized a cross-media campaign to share the message to the inhabitants of the North PED. A total of 18 homeowners signed up in the first round. Six demohouses were preselected and rated according six criteria:
- Is it representative for the district?
- Is there available physical space: does the house have enough space for sustainability measures or innovations?
- What is the potential of becoming energy positive?
- Unicity: does the house have any unique features that makes it a better candidate?
- Feasibility VS Investment: is the ratio between the investment and the energy savings reasonable?
- Innovativity of solutions: can the house become more sustainable using innovations?
After studying the six preselected candidates, three of them have been selected to be the final demo houses. A technical consultant has been involved to investigate and determine possible scenarios to make the three different households more energy positive. All the houses that were not selected were offered to be monitored as extra data for the project.
This household is located in an area where a study is ongoing to construct a district heating network. A majority of the Netherlands households is heated by individual gas boilers using natural gas. The government wants to ban these boilers in the upcoming years to decrease the overall CO2 emissions of the country. This change could become a problem for the houses poorly insulated since the gas boilers can deliver high amount of energy and the required heat but some innovative alternatives cannot or would be really expensive. All electric solutions for these households would require too much electricity and hydrogen would be too expensive as well. For these households, a district heating network could be a solution.
The initial district heating network would heat up water in a central place before distributing the heat to the individual households. The boiler in the households would be replaced by a heat exchanger, so the homeowners would not have to take any other actions within their households.
The temperature that is used to heat up the households in the Netherlands is around 70-75 degrees Celsius. When distributing this heat throughout a distribution network, temperature losses will occur. An alternative to this is a ‘low’ temperature district heating network (20-30 degrees Celsius) with an individual heating unit placed within the household itself to heat up the water which heats up the household or provides warm water to shower.
This last solution is a solution proposed to the homeowners. An air/water heat pump will ‘simulate’ the low temperature district heating network, which will feed to an individual heat pump that upgrades the temperature to the sufficient level for heating the household or for the homeowners to take a shower.
The general idea behind this design is that none of the homeowners should spend extra money on insulation measurements, since the system provides enough energy for the household. Insulation measurements of course are still interesting to save energy (and money) but are not necessary anymore.
The first of the newer households is a terraced household that already has some energy saving actions installed. The homeowners have several PV-panels as well as solar water heater. After consultations of a technical expert, for this household an acoustic heat pump was advised to install, to replace the gas boiler. Since the homeowners already decreased the temperature of their gas boiler, such a heat pump would produce sufficient energy to provide enough comfort for the homeowners.
The acoustic heat pump is a heat pump that does not have an outside unit. This is advantageous for this specific type of household, since there is few outside space around the house. The claim with this type of heat pump is that it is more silent than conventional heat pumps. Besides the amount of energy used by the system, production of noise is one of the things that will be measured. After installation of this equipment, together with the homeowners and the consortium partners, possible next home improvements steps will be determined.
For the last household, another system is being considered to be installed. The household has a good insulation rate, but has a disadvantage. The roof of the household is located to the North, which means that PV-panels (or PVT) have a relatively low yield (<50%). With the current prices of the installers, the homeowners do not consider this as an interesting investment. Together with an innovative company, the project and the homeowners are discovering the possibilities of hanging PV-panels vertically to the facade of the building. Both the technical and economical details are now being studied, as well as the permit process with the municipality.
The possible heating solution for this household would be a triple solar system. The triple solar system is a legally registered system, that contains a total solution for heating the household with a heating pump, PVT-panels and a booster. Together with the homeowners, the supplier, possible installers and consortium partners, the feasibility of this solution is studied.
To determine the energy flows within the households, all three have been equipped with smart plugs that communicate with a router. The consortium partner Sustainable Buildings (SB) had developed a dashboard on which the homeowners can see their energy use. Together with the coaches from GPO, the energy use will be analyzed and a plan will be made to help the homeowners save energy and therefore money. All major equipment installed in the households is measured and can be analysed.